Lumix G3, GX1, Fujifilm xpro, Nex7 , or M8

After my wife discovered the IQ of Leica M, now she wants a camera that can use my M lenses. We can't justify another M9, a used M8 seems the best choice. But I want to assure not to overlook the non-Leica solutions.

Lumix G3 or GX1 seem good candidates. So are fujifilm Xpro and Sony Nex. All can use Leica M lenses through adapter.

Any comment? what're the pros and cons of these four alternatives. The camera will be used for travel, outdoors activity, and family album.